Level Select
At the title screen were it says press start press Left, Up, X, Up, Right, Y
There will be a flash then when you start a new game there will be a list
of levels.
Infinite Health
At the title screen, press L + R + Y + A + Left (on the analog stick).
New Fireworks option
After you beat the game, go to options and select the new option called Fireworks.
